Quite numerous: Roscommon, Wexford, Meath etc. Anglo-Normans who settled in Wexford and Galway, whence one of the "Tribes of Galway". The Welsh "ff" for normal "f" arose in 16 cent. The name also occurs as French. Ir. Frinseach.

French:

numerous: E Ulster, Wexford, Waterford etc. Ir. Frínseach. One of the "Tribes of Galway" and long connected with Roscommon. Scottish & English, denoting French origin. IF.